ICE Assistant Secretary John Morton, seen here, wrote the Aug. 20 memo to Peter Vincent

Federal authorities have issued a new policy aimed at stopping deportation proceedings for some illegal immigrants, according to a memo issued by U.S. Immigration and Customs Enforcement.

The memo, which ICE released on Aug. 20, could affect up to tens of thousands of illegal immigrants who are married or related to a U.S. citizen or a legal resident who has filed a petition on their behalf. Illegal immigrants with criminal convictions will not qualify under the plan. ICE Assistant Secretary John Morton wrote the memo to Peter Vincent, principal legal adviser and head of the agency’s removal operations.

The memo directs ICE attorneys to check cases of detained illegal immigrants for any “serious” or “adverse” factors weighing against dismissal, including criminal convictions, fraud, national security and public safety considerations.

“If no investigations … or serious adverse factors exist, the offices of chief counsel should promptly move to dismiss proceedings,” the memo reads. “Once the Field Office Director is notified, the FOD must release the alien.”

The change in policy could affect thousands of the estimated 17,000 pending removal cases. According to ICE data, nearly 40,000 immigrants obtained U.S residency status due to sponsorship of relatives who were legal residents in fiscal year 2009. By comparison, more than 393,000 illegal immigrants were deported during that same span.

“Actions like this demoralize ICE agents who are trying to do their job and enforce the law,” Grassley told The New York Times. “Unfortunately, it appears this is more evidence that the Obama administration would rather circumvent Congress and give a free pass to illegal immigrants who have already broken our law.”

A Department of Homeland Security official told Fox News that the new policy was designed in July 2009 to improve docket efficiency.

“This administration is committed to smart, effective immigration reform, prioritizing the arrest and removal of criminal aliens and those who pose a danger to national security,” Rocha said in a statement. “In 2010 to date, ICE has removed more than 150,000 convicted criminals — a record number. [McAuleys’ World: It is estimated that there are between 4 million and 6 million illegals present in the Unites States with criminal conviction histories]

“ICE is not engaged in a ‘backdoor’ amnesty and has placed more people in immigration proceedings this year than ever before. ICE has implemented a new policy to expedite the removal of criminal aliens and those who pose a danger to national security by ensuring these cases are heard.”